Device for truing musical strings.



'PATENTED MAY 26, 1903.

C. A. GRAHAM. DEVICE FOR TRUING MUSICAL STRINGS. 7

APPLICATION FILED OCT. 22, 1902.

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PATENT Patented May 26, 1903.

OFFICE.

CLARENCE ARTHER GRAHAM, OF COLUMBUS, OHIO.

DEVI-CE FOR TRUING MUSICAL STRINGS.

SPECIFICATION forming part of Letters Patent No. 729,326, dated May 26,1903. Application filed October 22, 1902. Serial No. 128,270. (Nomodel.)

To aZZ whom it may concern.-

Be it known that I, CLARENCE ARTHER GRAHAM, a citizen of the UnitedStates, and a resident of Columbus, in the county of Franklin and Stateof Ohio, have invented a new and Improved Device for Truing MusicalStrings, of which the following is a full, clear, and exact description.

Strings for musical instruments formed of catgut and the like aregenerally of non-uniform diameter, and this defect impairs the musicalaccuracy of their notes.

The object of this invention is to overcome the defect mentioned, andthis end is attained by providing a peculiarly-constructed grindingdevice to the action'of which the string is subjected, so that thesurface of the string is out or ground down into :true uniformity. I I

This specification is amexact description of one example of myinvention, while the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forminga part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the views.

'Figure 1 is a perspective view of the invention, and Figs. 2 and 3 arecross-sectional views illustrating theinvention as used with strings ofdifferent diameters.

The device comprises two oppositely-arranged end or finger pieces a,between which extends a body-plate b, rigidly fastened to the end platesand provided on its inner side with an abrasive covering b.

ciudicatesa plate mounted to swing toward and from the plate 17 aroundthe axis indicated at the points 0 in'the drawings. This plate isprovided on its inner surface with an abrasive covering 0 similar to andopposing the covering 1).

The end or finger plates a are formed with a number of graduatedopenings ct therein, said openings being arranged in pairs the membersof which are one in each end plate and are longitudinally alined, sothat the string (indicated at no in the drawings) may pass through theend plates and between the two sections 1) and c.

d indicates a thumb-screw mounted in the body-plate b and adapted tolimit the movement of the plate 0 toward the body-plate,

K and 6 indicates a thumb-nut which works on a screw-stud e, pivoted tolugs 17 on the bodyplate (2 and adapted to lie loosely between theoppositely-located lugs c on the swinging plate c. By means of theseparts the plate a may be pressed firmly toward the plate 6, and by theadjustment of the screw d the plates 17 0 may be made to engage thestring with the required degree of force.

In using the invention the string is passed throughthat pair of openingsat which is suited to the general diameter of the string, andthen theelements d and e are adjusted to cause the abrasive surfaces 1) and c tobear properly against the string. After this has beeni'done the devicevshould be grasped in thefingers (this can be most conveniently efiectedby engaging the thumb and forefinger with the end plates a) and thedevice movedalong the string and simultaneously turned around thelongitudinal axis thereof. The'string should meanwhile be heldstationary, and by this operation every part of the surface of thestring may be reached by the abrading-surfaces, and the string will becut down into strictly-uniform diameter. It will be observed that duringthis operation the screw d prevents the swinging plate 0 from moving upany farther than the operator intends, which movement would otherwisetake place as the string is cut down by the action of the abrasivesurfaces on the body and swinging plates.

Various changes in the form, proportions,

and minor details of my invention may be resorted to without departingfrom the spirit and scope thereof. Hence I consider myself entitled toall such variations as may lie within the intent of my claims.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. A device for truing musical strings, comprising endmembers, and side plates having abrasive surfaces'connecting said endmembers, substantially as set forth.

2. A device for truing musical strings, comprising two end members, andtwo side members connecting the end members, one of said side membersbeing movable relatively to the other, substantially as set forth.

3. A; device for truing musical strings, comprising two end portionsprovided with series of graduated apertures in alinement, alongitudinally-extending member holding the said end portions rigidlyspaced apart, said longitudinal member having an abrasive surface, and asecond longitudinal abrading member pivoted to the aforesaid endportions, and movable on its pivot toward and from the rigid abradingmember, substantially as set forth.

4. Adeviee for truing musical strings, comprising two members havingopposing abrading-surfaces, one of said members being rigidly mouuted,the other member being pivotally mounted and movable from its pivottoward and from the rigid member, means for holding the strings in acertain and predetermined position relative to said abrading members,and means carried by the rigid member for limiting the movement of thepivoted member toward said rigid member, substantially as set forth.

5. A device for truing musical strings, comprising two members havingopposing abrasive surfaces, one of said members being rigid and theopposite member being movable, and means supported by one of the membersfor limiting the outward movement of the movable member away from therigid member, substantially as set forth.

(3. A device for truing musical strings, comprising a rigid abradingmember, and a movable abrading member, means carried by the rigid memberforlimiting the movementof the movable member toward said rigid member,and adjustable means supported by one of said members for limiting themovement of the movable member away from the rigid member, substantiallyas set forth.

7. Adevice for truing musical strings, comprising opposite end platesadapted to have a string passed through them, two members mounted on theend plates and having abrasive surfaces adapted to have a string passedbetween them, one of said members being swingable relative to theopposite member, and adjustable means carried by one of said plates forlimiting the movement of the swinging member toward and away from theopposite plate, substantially as set forth.

8. A device for truing musical strings, comprising orificed end plates,a body-plate held between them, a second plate movable toward and fromthe body-plate, said plates having opposing abrading-surfaces,adjustable means carried by one of said plates for limiting the movementof the movable plate toward the body-plate, and means for releasablyholding the movable plate engaged with said adjustable means.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

CLARENCE A ll'lllER GRAHAM.

Witnesses:

FRANK T. CLARKE, W. M. THOMPSON.

